Some would disagree that cancer and another disease-related morbidity, mortality, health care costs, and productivity losses associated with unhealthy lifestyle behaviors are increasing at an alarming rate. Studies show, however, that many people believe they have little ability to affect their cancer risk, despite clear evidence that healthy lifestyle behaviors can reduce the chance of developing the disease.

Research Emphases in Cancer Prevention and Control

Interest in cancer prevention and control research appears to be increasing as the toll of cancer and related health care costs grow, but funding still is quite limited compared with support for cancer detection and treatment research. Little cancer prevention and control research is behavioral or policy-oriented, although greater knowledge in both areas is essential to inform and improve primary and secondary prevention efforts. Most of the federally-sponsored cancer prevention research underway or planned emphasizes exploring genetic and/or molecular biologic indicators or predictors (markers) of cancer, metabolic pathways, and possible interventions to interrupt the multi-step cancer development process before invasive disease occurs. Although this work is important and should continue to be supported, it ignores the microenvironment.

Population-level benefits from this research are decades away. In the more immediate term, the principal causes of lung and numerous other cancers are amenable to change through behavioral and policy/environmental interventions, which offer the best chance of substantially reducing the cancer burden.

Sick Care, Not Well Care

Our health care system continues to be strongly oriented to the provision of acute care. Most physicians are trained principally to treat disease, not to help people remain well. In addition, the number of time physicians usually spend with each patient is extremely limited due to productivity pressures (i.e., to see a given number of patients each day, causing office visits to focus primarily, if not entirely, on the presenting complaint. As the Panel has noted in previous reports, procedures to address episodes of acute illness or treat chronic conditions are covered by health insurance, but reimbursement is scarce or nonexistent for services (excluding cancer screening for early detection) to maintain wellness or prevent diseases, such as counseling, education, outreach, and behavioral or psychosocial interventions.

Medicare reimbursement levels for medical services reflect a continuing lack of emphasis on disease prevention in the current health care system, and most private health plan reimbursement policies and schedules quickly mirror Medicare payment rates. Medicare reimbursement policies also influence state Medicaid payment rates. In the private sector, a major barrier to coverage for behavioral or other cancer risk-reducing interventions has been the short-term profit mentality of publicly-held private insurers and many corporations. Employee turnover and resultant changes in health plan participation have made both insurers and employers hesitant to invest in preventive interventions because of doubts that they would be the ones to enjoy whatever health care cost savings might accrue. 

Wellness Initiatives – Bridging the Gap, Promoting a Culture of Wellness

In growing numbers, however, larger employers and some state and local governments are attempting to counter rising health care costs, productivity losses, and the health care system’s lack of emphasis on disease prevention by devising and implementing wellness programs. Regardless of their motivation, these programs are promoting a culture of wellness and individual empowerment regarding personal health that has not previously existed in many segments of the population. In addition, numerous publicly-sponsored and other health promotion-oriented Web sites now offer tools to help people adopt healthier lifestyles.

This is a promising trend, but many millions of Americans will continue to lack access to wellness services such as these, perhaps for many years. Promoting a culture of wellness may be most challenging among people in part-time and low paying jobs and the unemployed who lack employer health or Medicaid benefits, those without a usual source of care, individuals without computer access, those less educated and/or health literate, those living in neighborhoods in which it is unsafe to exercise outdoors and where fresh food access is limited, and individuals whose first language is not English. A number of local governments and community organizations, in some cases with Federal financial assistance, are attempting to reach these populations with culturally tailored fitness, nutrition, and other interventions.

Reducing Cancer Risk Through Diet, Nutrition, and Physical Activity

The term,“energy balance,” as applied to human health, typically refers to the integrated effects of diet, physical activity, and genetics on growth and body weight over an individual’s lifetime. Increasingly, scientists are becoming aware of the importance of understanding the effects of energy balance on cancer development and progression and on cancer survivors’ quality of life post-treatment. Weight, body composition, physical activity, and diet affect numerous physiologic systems and therefore can alter the cancer process at many points. 

Obesity, Diet, Nutrition, and Cancer

Almost two-thirds of the U.S. adult population is overweight, and approximately half of those individuals are obese. It has been estimated that if current trends persist, 74 percent of the adult population will be overweight or obese by 2010 and by 2016, more than half of the population is likely to be obese. As an overall public health problem, obesity due to unhealthy lifestyle may be challenging tobacco use in its population impact – certainly with respect to associated morbidity – and has led some to believe that it could result in shortened life expectancy in the relatively near future. Estimates of obesity-related mortality vary, but a 2005 Centers for Disease Control and Prevention (CDC) study estimated that approximately 112,000 deaths are associated with obesity annually in the United States, making obesity the second leading contributor (after tobacco use) to premature death.

Obesity rates vary considerably among population groups, with higher rates observed among the poor and some ethnic/minority groups. The escalating rates of overweight and obesity among children and adolescents are of great concern since these individuals have as much as an 80 percent risk of becoming overweight adults.

The list of cancers associated with obesity continues to grow; established or suspected obesity-related cancers include:

• Breast (postmenopausal)

• Prostate (advanced)

• Pancreas

• Esophagus (adenocarcinoma)

• Gastric Cardia (adenocarcinoma)

• Endometrium

• Colon and Rectum

• Liver

• Gallbladder

• Kidney (renal cell)

• Non-Hodgkin’s Lymphoma

• Multiple Myeloma

• Leukemia

• Stomach (men)

• Ovary

• Uterus

• Cervix

Some of these correlations between obesity and cancer risk, incidence, and prognosis are better established than others. Studies have found overall cancer death rates as much as 50 percent higher in obese men compared with their normal-weight counterparts, and more than 60 percent higher cancer death rates among obese women.

Efforts to halt and reverse current obesity trends are unlikely to succeed without the participation and collaboration of governments, non-governmental organizations, industry, educators, and individuals. For example, current agricultural and public health policy is not coordinated – we heavily subsidize the growth of foods (e.g., corn, soy) that in their processed forms (e.g., high fructose corn syrup, hydrogenated corn and soybean oils, grain-fed cattle) are known contributors to obesity and associated chronic diseases, including cancer.

The upcoming reauthorization of the Farm Security and Rural Investment Act of 2002 (the Farm Bill) provides an opportunity that must not be missed to strongly increase support for fruit and vegetable farmers, improve the national food supply, and enhance the health of participants in the national school lunch, food stamp, and Women, Infant, and Children food assistance programs. Greater efforts are needed to improve the nutrition environment, particularly in lower-income areas, to ensure that all people have physical and financial access to healthy food. Although some school districts are attempting to improve the school nutrition environment, the quality of most school food service offerings is poor due to the use of processed government surplus foods and the availability of unhealthy foods in school vending machines, cafeterias, and school stores.

Food marketing, particularly to children, emphasizes unhealthy food products. Currently, such marketing is regulated only by voluntary guidelines established by the food and beverage industries. In addition to more effective oversight of food advertising, coordinated public education is needed to teach children and adults about healthy eating to avoid cancer, heart disease, hypertension, and diabetes. Constructive involvement of the media will be essential to reach these objectives.

The links between cancer, diet, and obesity have not been accepted sufficiently by the health insurance industry to motivate widespread coverage for health-promoting/cancer prevention services such as nutrition counseling or obesity-related treatment services. Obesity itself typically is not a covered medical condition. An individual must develop an established obesity-related condition (e.g., diabetes, hypertension, heart disease, high cholesterol) to receive reimbursed treatment. However, the treatment generally only covers services to control the obesity-related disease, but not to address its underlying cause. This situation reflects the overall acute care orientation of the health system; for example, the services of a nutritionist or dietitian seldom are reimbursed outside of a specialized cardiac rehabilitation or diabetes management program. Health care providers have a crucial role in helping patients understand the meaning of energy balance and body mass index (BMI), the necessity of reducing caloric intake in order to lose weight, and the increased risk for many cancers due to obesity.

Employers can help employees control their weight and reduce health care costs related to cancer and other chronic diseases by offering healthier choices at worksite food service facilities and vending machines, manipulating prices to make healthier options more appealing than unhealthy ones, and actively encouraging employee fitness.

Thus, multi-pronged nutritional interventions have the potential to increase individual awareness of the relationship between diet and cancer and also reach the family, community, and society as a whole. Barriers to healthy eating must be removed and greater resources should be provided for vulnerable populations. In addition, support is needed for people who are making healthy changes, and population-level nutrition policies are required.

Physical Activity and Cancer

The importance of physical activity in cancer prevention, independent of diet and obesity, is becoming better understood. According to the 2005 Behavioral Risk Factor Surveillance Survey (BRFSS) data, a quarter of all adults engage in no leisure-time physical activity. Less than half engage in moderate or vigorous physical activity as recommended by CDC. By age 18 to 22 years, only 26 percent of males and 12 percent of females engage in moderate or strenuous activity at least five times per week. Inactivity during childhood and adolescence is of particular concern because it increases the likelihood of being inactive as an adult, and less active adults are at greater risk of developing colon cancer, heart disease, and high blood pressure.

Cancers with an established or suspected association with physical inactivity include:-

• Colon

• Rectum

• Endometrium

• Breast

• Kidney

• Ovary

• Prostate

• Lung

• Testis

Though findings to date vary by cancer site and population studied, inactivity generally is associated with higher cancer risk and protective effects of exercise increase with frequency, intensity, and duration of activity. Though most research to date has focused on the efficacy of physical activity in cancer prevention, accumulating evidence also demonstrates that exercise influences other aspects of the cancer experience, including cancer detection, coping ability, rehabilitation, and survival.

As with obesity, diet, and nutrition, numerous initiatives and Web sites have been established by Federal and non-governmental organizations to encourage people to become more active. Those that have been evaluated have shown variable success and may be most effective as part of a multi-pronged physical activity intervention. Numerous states and localities are launching programs and environmental improvements to increase physical activity among residents, usually as part of broader wellness initiatives.

The built environment is a key influence on the likelihood that people will adopt and maintain an active lifestyle. Research on adults has found a direct relationship between the convenience of places to walk and the proportion of adults meeting current activity recommendations. In many neighborhoods, lack of sidewalks, inadequate lighting, and other safety concerns are significant disincentives to outdoor physical activity. Many neighborhoods lack playgrounds and other recreational facilities; in others, available facilities need substantial refurbishment to be both safe and attractive. Moreover, as suburbs radiate further from city centers, residential communities are being placed far from employment centers and shopping hubs, necessitating auto travel to commute to jobs and accomplish shopping and other routine tasks.

The decline of physical education in schools, unfortunately, has coincided with unhealthy changes in family eating patterns (e.g., increase in the percentage of restaurant meals eaten, eating “on-the-run”), increased sedentary leisure activities, and other changes in common behavior patterns.

For example, few children still walk to school. Diminished participation in physical education is one of several factors contributing to increasing obesity rates among children and teens. Physical education has been all but eliminated in many schools, largely due to pressures to improve performance in core academic subjects. In schools that offer physical education, classes usually are large, limiting the amount of time each child can participate actively. Only a handful of states measure children’s body mass index and report the results to parents. In addition, most schools still offer little more than traditional team sports; some are beginning to focus on individually-oriented activities that all students can enjoy throughout life, regardless of baseline skill levels.

Widely available and increasingly diverse forms of media entertainment are key contributors to sedentary lifestyles that are a major factor in climbing obesity rates. According to one estimate, children aged 8 to 18 years spend an average of 6.5 hours per day either in front of a screen (e.g., television, video console, non-homework related computer) or listening to music. Data on adult use of media entertainment are scarce, but some studies suggest substantial levels of use, particularly among adults who also report engaging in no physical activity. Moreover, the ability of media coverage to shape public opinion and reinforce various behaviors (e.g., perceptions of fitness and physical activity as normative and desirable behaviors) is extremely powerful. This influence should be used to promote healthy lifestyles that would help reduce the burden of cancer and other chronic diseases.

Though still not commonplace, some employers are trying to encourage recreational physical activity among employees. These efforts usually are part of a broader wellness program that may target obesity, diabetes and hypertension control, and other health issues. The motivation typically is to induce employees to improve their health in order to reduce health benefit costs and improve worker productivity.

As is true regarding diet and nutrition counseling, most primary care providers do not routinely counsel patients about the importance of physical activity and the level of activity needed to lose weight and maintain a healthy weight. Like nutrition counseling, physical activity counseling or services seldom are reimbursed by public or private health insurance plans except in the context of cardiac rehabilitation or physician-prescribed physical therapy.

Because physical activity is not a routine part of most Americans’ lives, individuals and families will need to find and create opportunities to become more active. Individuals also can advocate for themselves and their families for changes to make neighborhoods more exercise-friendly for adults and children, and for meaningful physical education in schools.

Reducing Cancer Risk by Eliminating Tobacco Use and Exposure

Tobacco use is the number one cause of preventable death in the United States, and the second leading cause of death in the world. It is estimated that if current tobacco use trends continue, by 2020 approximately 10 million tobacco-related deaths will occur each year, with more than a billion tobacco-related deaths in the 21st century

Tobacco Use and Cancer

The only known way to reduce tobacco-related death and disease is the prevention and cessation of tobacco use and environmental tobacco smoke (ETS) exposure. In effect, if the population ceased smoking, this single behavior change would be tantamount to a vaccine against one-third of cancer deaths. Half of all long-term smokers – particularly those who began smoking as teens – will eventually die prematurely from a disease caused by tobacco; half of these people will die in middle age, losing on average 20 to 25 years of life expectancy.

Nicotine in tobacco causes addiction as powerful and self-reinforcing as addiction to drugs such as cocaine and heroin. Tobacco use has been established unequivocally as a causative or contributory agent in the development of a growing list of cancers:

• Lung

• Trachea

• Bronchus

• Esophagus

• Oral Cavity

• Lip

• Nasopharynx

• Nasal Cavity

• Larynx

• Paranasal Sinuses

• Stomach

• Bladder

• Kidney

• Pancreas

• Uterine Cervix

• Acute Myeloid Leukemia

Susceptibility to tobacco carcinogens and subsequent cancer development is believed to be affected by numerous factors, including but not limited to familial genetic predisposition, other genetic alterations, DNA repair capacity, differences in carcinogen metabolism, defects in cell signaling pathways, cell/environment interactions, and chronic inflammatory processes. Smoking also is a major cause of heart and cerebrovascular disease, chronic bronchitis, and emphysema.

In 2005, 20.9 percent of U.S. adults (18 years of age and older) were current cigarette smokers; smoking prevalence remains higher among men (23.9 percent) than among women (18.1 percent). Smoking prevalence is higher among the poor compared with those with more resources, varies considerably among racial/ethnic groups, and generally decreases with increasing educational level.

Several population groups are particularly vulnerable to tobacco initiation, continued use, and consequent disease. Perhaps the most important of these are youth; since the younger people are when they begin to smoke, the more likely they are to become addicted adult smokers. More than 80 percent of adult smokers become addicted as teenagers. Nicotine-addicted adolescents typically overestimate their ability to stop smoking when they choose, and most relapse after a quit attempt. Of particular concern, the decline in teen smoking rates that began in the late 1990s appears to have flattened, in part due to the introduction of numerous new tobacco products designed to appeal to young people (e.g., flavored cigarettes and cigars). Similarly, use of smokeless tobacco (ST) products by youth declined after the mid-1990s but have begun to increase again, in part due to the introduction of many new youth-targeted flavored ST products. ST use is strongly associated with smoking initiation. Other populations of special concern with regard to smoking initiation and ongoing tobacco use include young adults, women, racial/ethnic minorities, the poor, active military personnel, veterans, cancer survivors, persons with mental illness, and the gay and lesbian communities.

As is true concerning efforts to address poor diet and nutrition, physical inactivity, obesity, and the added cancer risk attributable to these lifestyle factors, numerous stakeholders are involved in the current tobacco problem in the United States and worldwide – and its solution. Evidence-based methods exist to reduce tobacco use initiation and facilitate cessation (e.g., tobacco tax increases, smoke-free environments, anti-smoking campaigns, and education) and to treat tobacco users (pharmacologic and behavioral interventions). These tools must be applied more broadly and in concert at both individual and population levels to substantially reduce the burden of cancer due to tobacco use.

It is not an exaggeration to characterize the tobacco industry as a vector of disease and death that can no more be ignored in seeking solutions to the tobacco problem than mosquitoes can be ignored in seeking to eradicate malaria. Over the past half century, the industry has developed highly sophisticated strategies to oppose effective public policies and programs to reduce tobacco consumption, reaching into all levels of the political system and maintaining public denial in the face of overwhelming scientific evidence of addiction and harm from tobacco products. The tobacco companies also have manipulated product design and contents to increase their addictiveness and appeal.

Key actions needed at the Federal level to reduce the disease burden of the tobacco pandemic in the United States and globally include ratifying the Framework Convention for Tobacco Control, authorizing the Food and Drug Administration to regulate the content and marketing of all tobacco products, increasing the Federal tobacco excise tax, and excluding tobacco and tobacco products from all international trade agreements. In addition, the Federal commitment to tobacco control research does not reflect the burden of disease caused by tobacco and must be strengthened.

Despite having ample funds with which to administer effective tobacco control programs, only a handful of state governments have ever supported tobacco control efforts at the level recommended by CDC – a mere 7.3 percent on average of state tobacco tax revenues and annual payments under the 1998 Master Settlement Agreement (or similar state/ industry settlements). Moreover, for reasons including industry and political pressures and competing priorities (e.g., highway construction, debt service), many previously robust programs have had most or all of their funding withdrawn. The tobacco companies have been quick to fill this void with vastly increased product promotion to targeted populations. States need to restore and/or increase funding for tobacco control and continue to raise excise taxes, which have been shown to discourage tobacco use, particularly by youth.

Important tobacco control investments and partnerships exist among numerous non-governmental organizations and with Federal agencies such as CDC and the National Cancer Institute. These should be continued and expanded.

Media portrayals of smoking as a pleasurable, attractive, and normal adult activity are enormously powerful influences on young people’s attitudes about smoking and the likelihood that they will use tobacco. Therefore, the media have a significant moral responsibility to not promote the use of deadly tobacco products and can have a far-reaching influence in actively discouraging tobacco use.

Direct health care costs due to tobacco-related disease are now estimated at $75 billion annually, and indirect costs exceed $81 billion. Smokers have higher overall health care costs compared with nonsmokers, and family members of people who smoke often have higher health care costs compared with families in which no one smokes. It is in the mutual interests of employers, public and private sector health insurers, and the health care system to work together to provide tobacco use cessation services to all who need them and thereby reduce health care costs lost productivity and suffering due to cancer and other diseases caused by tobacco.

Clearly, the most important thing individuals can do to reduce tobacco-related cancer risk is to cease using any form of tobacco. Individuals also can support anti-tobacco policies and programs (e.g., to prevent youth access to tobacco and improve anti-tobacco education in schools) and support mandated insurance coverage for comprehensive tobacco cessation services.

Environmental Tobacco Smoke (ETS) and Cancer

Cigarette smoke contains more than 4,000 chemicals (e.g., cyanide, formaldehyde, benzene, arsenic, DDT, acetylene, ammonia), including 69 known carcinogens as well as poisonous gases such as nitric oxide and carbon monoxide. These chemicals come from the tobacco itself and the combustion of the myriad substances added by manufacturers to make tobacco products more palatable. ETS causes approximately 3,000 lung cancer deaths each year among nonsmokers in the United States and is a significant contributor to cardiac, respiratory, and other diseases in individuals exposed to it. In total, ETS exposure claims the lives of approximately 38,000 nonsmokers annually. There is no safe level of exposure to ETS.

The momentum toward passage of smoke-free laws has been gathering speed and received a significant push with the publication of the Surgeon General’s report on ETS. In addition to protecting nonsmokers, smoke-free laws are estimated to help the 70 percent of smokers who want to quit by providing them with public environments free from any temptation or pressure to smoke.

The strongest resistance to smoke-free ordinances typically comes from bar and restaurant owners, who fear a significant loss of business if smoking is prohibited on their premises. Such fears have proven to be unfounded. As of July 3, 2007, approximately 162 million Americans are living in locales with smoke-free ordinances. During the period from the beginning of the Panel’s meetings (September 2006) until the publication of this report (August 2007), at least 133 new smoke-free laws were passed by the state, county, and local governments. However, despite the dramatic increases in the passage of smoke-free workplace laws, an estimated 30 percent of workers continue to be exposed to ETS, and exposure varies considerably by occupation. Bar and restaurant workers are among the most highly exposed.

Tobacco industry attempts to thwart smoke-free policies have been well documented. Smoke-free laws pose a major threat to tobacco sales because they reflect a changing culture in which tobacco use is becoming increasingly unacceptable. The industry continues to oppose new smoke-free laws and is actively pursuing ways of replacing revenues lost due to smoke-free ordinances and laws. To counter decreasing tolerance for smoking and smoke exposure, the tobacco companies are developing and marketing a growing number of smokeless products, including some that are spotless. These products allow smokers to maintain nicotine dosage and still comply with smoking restrictions. They also help the industry avoid losing as customers smokers who quit using cigarettes.

Some individuals and families still permit smoking in the home, in the car, and around children, exposing family members and visitors to significant ETS levels. Changing this situation will require personal action. Individuals also can protect themselves and their families from ETS exposure by patronizing smoke-free businesses and vote for smoke-free local and state ordinances. 

Conclusions

The President’s Cancer Panel has long maintained that participants in the National Cancer Program include not just research institutions, health care entities, and patient advocates, but all of the institutions, organizations, industries, and individuals that by their action or inaction contribute to reducing or exacerbating the national burden of cancer. In large measure, cancer researchers and the acute care health system have been charged, albeit erroneously, with addressing the epidemics of obesity- and tobacco-related cancer morbidity and mortality. They cannot do this without a change in focus, and they cannot do it alone. Policy decisions that would enable more people to choose cancer risk-reducing behaviors have been limited both in number and scope. Yet cancer control research evidence clearly recognizes the critical need for legislative, policy, and environmental changes to support individual behavior change. The public health infrastructure – which has enormous potential for promoting healthy behaviors – is underdeveloped and undervalued. The important roles of government at all levels, the health care and insurance systems, and entities not usually considered to be participants in the National Cancer Program – the media, city planners, employers, the agricultural system, the educational system, the food, beverage, and restaurant industries, to name only a few – have been underappreciated.

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